1. Field of the Invention
The invention relates to providing emergency route guidance to guide users away from a disaster, and more particularly, to using a portable electronic device to provide navigation instructions away from a disaster when the user requests emergency route guidance from the portable electronic device.
2. Description of the Prior Art
Global Positioning System (GPS) based navigation devices are well known and are widely employed as in-car navigation devices. Common functions of a navigation device include providing a map database for generating navigation instructions that are then shown on a display of the navigation device. These navigation devices are often mounted on or in the dashboard of a vehicle using a suction mount or other mounting means.
The term “navigation device” refers to a device that enables a user to navigate to a pre-defined destination. The device may have an internal system for receiving location data, such as a GPS receiver, or may merely be connectable to a receiver that can receive location data. The device may compute a route itself, or communicate with a remote server that computes the route and provides navigation information to the device, or a hybrid device in which the device itself and a remote server both play a role in the route computation process. Portable GPS navigation devices are not permanently integrated into a vehicle but instead are devices that can readily be mounted in or otherwise used inside a vehicle. Generally (but not necessarily), they are fully self-contained—i.e. include an internal GPS antenna, navigation software and maps and can hence plot and display a route to be taken.
Personal navigation devices strive to guide users on the best possible route in order to minimize the time needed to travel from one point to another. However, in the event of a disaster occurring near the user, the user may be less concerned about arriving at a particular destination, and may be more concerned about simply getting away from the user' s current location.
Recent natural disasters around the globe highlight the possible need for users to be able to receive guidance to a safe area. How to get to a safe area might be known for some local residents. Unfortunately, tourists visiting an unfamiliar city or country cannot easily benefit from the knowledge of the local residents. In the past, confusion among drivers has even caused drivers to drive their vehicles straight toward a disaster, such as a tsunami or flood, instead of driving away from it. For tourists not very familiar with their current location, finding an appropriate destination to use for escaping a disaster would be very difficult.
Even for those users having a navigation device, choosing an escape route is not always a simple matter in the case of a disaster. This is because there is not usually a given destination that the user must enter into the navigation device. Instead, the user often is trying to get away from the user' s current location. In other words, the navigation device needs to guide the user away from a given location, which is the opposite of the navigation device' s typical job of guiding the user to a destination. Therefore, there exists a need for a navigation device which can provide emergency route guidance in order to guide users away from a disaster.